Stabilizing apparatus for ships



Oct. 18, 1966 H, D, FANSHAWE 3,279,409

STABILIZING APPARATUS POR SHIPS Filed Nov. 27, 1964 /Z/m/ A f 4/42240 M530 5/ HG2.

INVENTOR HEW D. FANSHAWE ATTORNEYS United States Patent Giice 3,279,409 Patented oet. 18, 196e 3,279,409 STABILIZING APPARATUS FOR SHIPS Hew D. Fanshawe, North Berwick, East Lothian, Septland, assignor to Brown Brothers & Co. Limited, Edluburgh, Scotland, a corporation of Great Britain and Northern Ireland Filed Nov. 27, 1964, Ser. No. 414,136 Claims priority, application Great Britain, Nov. 28, 1963 47,143/ 63 6 Claims. (Cl. 114-125) This invention relates to stabilizing apparatus for ships, of the type in which inter-connected liquid-holding means are provided at opposite sides of the hull of the ship.

To provide maximum stabilizing action in stabilizing apparatus of the type referred to it is essential that the liquid-holding means at one side of the ship should be emptied and the liquid-holding means at the other side of the ship should be iilled. For gravity flow this requires a considerable angle of roll to -be developed and for transfer of the liquid by a pumping system the system must operate in the presence of a widely varying head which varies from a minimum value, when the liquid-holding means to which the pump is discharging is empty, to a maximum value when the liquid-holding means is full with a superimposed positive or negative head which results from the rolling motion of the ship and the instantaneous value of which depends on the langular position of the ship at each instant. This means that even when the apparatus is being used for roll reducing the angle of roll of the ship must be quite considerable to ensure transfer of an eiiective quantity of liquid from one liquid-holding means to the other, or in a stabilizing system it is necessary to incorporate a large pump capable of transferring the liquid at a high speed and against the maximum head yet which for considerable periods of its operation will be operating with the gravity head assisting the pump.

A stabilizing apparatus according to the invention incorporates two liquid-holding means normally on the same level, each liquid-holding means consisting of a series of closed liquid-holding compartments all on the same level and pressurized in ascending steps of pressure, means for connecting each compartment except the compartment at lowest pressure of one selected liquid-holding means at a point below its minimum liquid level t-o the compartment of the other liquid-holding means pressurized to the next lower step of pressure at a point below its minimum liquid level, pump means having its inlet connectible to said compartment at lowest pressure of said selected liquid-holding means and its discharge connectible to the compartment at highest pressure of said other liquid-holding means, corresponding compartments of the two liquid-holding means at the same pressure being interconnected at points above the maximum liquid level in the compartments.

Corresponding compartments of the two liquid-holding means at the same pressure may be additionally connectible to one another 'at points below the minimum liquid level ofthe compartments.

In one construction each compartment is associated with a liquid-transfer duct leading from the compartment to a multiple-passage valve device having a plurality of passages the number of which is one greater than the number of compartments in each liquid-holding means and two sets of ganged valve membersy disposed at opposite ends of the passages and so arranged and interconnected with one another that each compartment except the lowest pressure compartment of one selected liquidholding means may be put simultaneously into communication by way of one of the passages in the valve device with the compartment of next lower pressure ofthe other liquid-holding means, the pumping means being located in a passage interconnecting the passages in the multiplep'assage valve device connectible to the lowest pressure and the highest pressure compartments of each liquidholding means.

The multiple-passage valve device may be so contrived that each compartment in one liquid-holding means may also be put in communication with the corresponding compartment of the other liquid-holding means instead of with the compartment of next lower pressure.

The multiple-passage valve device may consist of a number of passages in hydraulic parallel with a ilap valve member located lat each end, all the flap valve members at a respective end being ganged so that they move simultaneously and provide a connection alternatively from each passage in the valve to one or the other duct connected to adjacent compartments in a respective set ot liquid-holding means.

The valve members may be connected to roll-sensing apparatus e.g., of the type incorporating at least one gyroscope so that at the commencement of a roll the valve members are moved to the positions to connect each compartment on the appropriate side of the ship to the compartment of next lower pressure on the opposite side of the ship, and the lowest pressure compartment on said appropriate side of the ship to be connected with the passage in the multiple-passage valve open to the inlet of the pump, the highest pressure compartment on said opposite side of the ship being connected to the passage of the multiple-passage valve device open to the discharge of the pump.

A practical embodiment 'of the invention is illustratedv in the accompanying diagrammatic drawings in which FIG. l yis a plan view of stabilizing apparatus 'and FIG. 2 is an end elevation of the apparatus.

In the drawings, 1 and 2 denote two liquid-holding means disposed respectively towards opposite sides of a ship, the liquid-holding means 1 consisting of a series of' closed liquid-holding compartments 1A, 1B, 1C pressurized in ascending steps of pressure from 1A to 1D, and the liquid-holding means 2 consisting of a series olf closed liquid-holding compartments 2A, 2B, 2C and 2D pressurized in ascending steps of pressure from 2A to 2D, all the compartments 1A to 1D and 2A to 2D being on the same level. The compartments 1A to 1D are respectively associated with liquid-transfer ducts 3A to 3D and the compartments 2A to 2D are associated with liquid-transfer ducts 4A to 4D, the liquid-transfer ducts 3A to 3D and 4A to 4D each leading from the respective compartment toa multiple-passage valve device 5 having a plurality of passages 5A, 5B, 5C, 5D and 5E, the number of these passages being one greater than the number of compartments in each liquid-holding means 1 and 2. The multiple-passage valve device 5 contains two sets of ganged valve members 6 and 7, the members 6 being all connected to a liquid-pressure operating cylinder 8, and the valve members 7 being all connected to a liquid pressure operating cylinder 9. The cylinders 8 and 9 are connected to be under the control of a rollsensing apparatus 10. The valve members 6 and 7 are so arranged that each intermediate compartment in one liquid-holding means may be put into communication with the corresponding-compartment of the other liquidholding means or with the compartment of next higher pressure step or next lower pressure step in the other liquid-holding means and simultaneously the compartment of lowest pressure in said one liquid-holding means is put into communication with the passage 5A of the valve device 5, and the compartment of highest pressure 3 in the other liquid-holding means is put into communication with the passage 5E of the valve device S. The passages 5A and 5E are connected to one another by a duct 11 in which a pump 12 is intercalated. AIn the setting 'of the valve members 6 and 7 illustrated the compartments 1B, 1C and 1D are respectively connected to the compartments 2A, 2B and 2C of next lower pressure step and the compartment 1A is connected to the passage 5A and the compartment 2D is connected to the passage 5E. 13A, 13B, 13C and 13D denote pipes connecting correspending compartments 1A, 2A; 1B, 2B; 1C, 2C; and 1D, 2D at points above the maximum fluid level in the compartments. 14 denotes liquid in the compartments.

In practice, when a roll begins to develop in a ship the valve members 6 and 7 of the multiple passage valve device 5 are illustrated as set by the roll-sensing apparatus to counteract a roll tending to raise the side of the ship which is at the right of the drawings. Liquid immediately starts to oW through the valve device 5 from each compartment 1B, 1C and 1D to the corresponding compartments 2A, 2B, 2C of next lower pressure on the other side of the ship by the pressure head in the compartments at higher pressure and liquid is pumped by the pump 12 from the lowest pressure compartment 1A to the highest pressure compartment 2D. According as the maximum bias or only a proportion of the maximum bias is required to counteract the incipient roll, so the valve members 7 i.e., the valve members on the side towards which the liquid is moving permit the pressure head to move the liquid with increasing velocity for a longer or shorter period of time, thereafter changing to connect compartments at the same pressure, i.e., to connect the compartment 1B to the compartment 2B and so on. It will be appreciated that the kinetic energy of the liquid in the ducts 3A, 4A; 3B, 4B; 3C, 4C; 3D, 4D connecting the various compartments will not be destroyed by this change so that ow'will continue under a head reduced by one step of pressure, any further iiow in these conditions reducing the pumping required -in preparation for the return or part return of the liquid to the original compartment to counteract the incipient-return roll, or neutralize the bias as necessary. If it is necessary to maintain full the compartment already iilled after the kinetic energy of the moving liquid has been absorbed the valve members 7 are returned to the positions illustrated.

Theoretically in the apparatus according to the invention the greater portion of the liquid can be transferred by pressure head Without any rolling action of the ship at all. It will, however, be understood that some rolling action -is necessary to operate the roll-sensing apparatus 10 which controls operation of the valve members 6 and 7. Only the remaining portion of the operating liquid requires to be pumped and as the difference between the minimum head and the maximum head against which the pump 12 is to operate is only the sum of the changes in depths of liquid at the suction and delivery olf theV pump 12 the pump 12 is operating against a load which lluctuates to a comparatively small extent. The pump may thus be smaller than in known types of installations of the same stabilizing capacity because it requires to pump only a fraction of the total quantity of operating liquid and it may be arranged to operate continuously nearer its maximum eiciency than a corresponding pump in an existing installation since there is a smaller variation between the minimum and maximum operating heads. The apparatus described also operates to provide full stabilization with small angles of roll.

The installation described is of particular value where headroom is severely limited as the height of each liquidholding means is the height of one compartment only.

What is claimed is:

1. A stabilizing apparatus incorporating two liquidholding means normally on the same level, each liquidholding means -consisting of a series of closed liquid-holding compartments all on the same level and pressurized in ascending steps of pressure, means for connecting each @compartment except the compartment at lowest pressure of one selected-liquid-holding means at a point below its minimum liquid level to the compartment of the other liquid-holding means pressurized to the next lower step of pressure 4at a point below its minimum liquid level, pump means having its `inlet connectible to said compartment at ylowest pressure of said selected liquid-holding means and its discharge :connectible to the compartment at highest pressure of said other liquidholding means, corresponding compartments of the two liquid-holding means at the same pressure being interconnected lat points above the maximum liquid level in the compartments.

2. A stabilizing apparatus as claimed in claim 1 in which corresponding compartments of the two liquidholding means at the same pressure are additionally connectible to one another at points below the minimum liquid level of the compartments.

3. A stabilizing apparatus as claimed in claim 1 in which each 'compartment is associated with a liquidtransfer duct leading from the compartment to a multiplepassage valve device having a plurality of passages the number of which is one greater than the number of compartments in each liquid-holding means and two sets of ganged valve members disposed at opposite ends of the passages and so arranged and interconnected with one another that each compartment except the lowest pressure compartment of one selected liquid-holding means is put simultaneously into communication by Way of one of the passages in the valve device with the compartment of next lower pressure of the other liquid-holding means, the pumping means being located in a passage interconnecting the passages in the multiple-passage valve device connectible to the lowest pressure and the highest pressure compartments of each liquid-holding means.

4. A stabilizing apparatus as claimed in claim 3 in which the multiple-passage valve device is so contrived that each compartment in one liquid-holding means may be put in communication with the corresponding compartment of the other liquid-holding means as an alternative to being put in communication with the compartment of next lower pressure.

5. A stabilizing apparatus as claimed in claim 3 in which the multiple-passage valve device consists of a number of passages in hydraulic parallel with a ap valve member located at each end, all the flap valve members at a respective end being ganged so that they move simultaneously and provide a connection alternatively from each passage in the valve to one or other duct connected to adjacent compartments in a respective set of liquid-holding means.

6. A stabilizing apparatus as claimed in claim 3 in which the valve members are connected to roll-sensing apparatus providing control of movement of the valve members in such wise that at the commencement of a roll the valve members are moved to the positions to connect each compartment on the appropriate side of the ship to the .compartment of next lower pressure on the opposite side of the ship, and the lowest pressure compartment on said appropriate side of the ship to be connected with the passage in the multiple-passage valve open to the inlet of the pump, the highest pressure compartment on said opposite side of the ship being -connected to the passage ofthe multiple-.passage Valve device open to the discharge of the pump.

No references cited.

MILTON BUCHLER, Primary Examiner.

T. M. BLIX, Assistant Examiner. 

1. A STABILIZING APPARATUS INCORPORATING TWO LIQUIDHOLDING MEANS NORMALLY ON THE SAME LEVEL, EACH LIQUIDHOLDING MEANS CONSISTING OF A SERIES OF CLOSED LIQUID-HOLDING COMPARTMENTS ALL ON THE SAME LEVEL AND PRESSURIZED IN ASCENDING STEPS OF PRESSURE, MEANS FOR CONNECTING EACH COMPARTMENT EXCEPT THE COMPARTMENT AT LOWEST PRESSURE OF ONE SELECTED LIQUID-HOLDING MEANS AT A POINT BELOW ITS MINIMUM LIQUID LEVEL TO THE COMPARTMENT OF THE OTHER LIQUID-HOLDING MEANS PRESSURIZED TO THE NEXT LOWER STEP OF PRESSURE AT A POINT BELOW ITS MINIMUM LIQUID LEVEL, PUMP MEANS HAVING ITS INLET CONNECTIBLE TO SAID COMPARTMENT AT LOWEST PRESSURE OF SAID SELECTED LIQUID-HOLDING MEANS AND ITS DISCHARGE CONNECTIBLE TO THE COMPARTMENT AT HIGHEST PRESSURE OF SAID OTHER LIQUIDHOLDING MEANS, CORRESPONDING COMPARTMENT OF THE TWO LIQUID-HOLDING MEANS AT THE SAME PRESSURE BEING INTERCONNECTED AT POINTS ABOVE THE MAXIMUM LIQUID LEVEL IN THE COMPARTMENT. 